本标准规定了SAE线性令牌传递总线（LTPB）接口单元的特性。LTPB提供了一个高可靠性、高带宽、低延迟的串行互连网络，适用于实时军事和商业应用。可以实现多个冗余数据路径，以增强需要这些属性的应用程序的可靠性和生存能力。令牌传递和数据交换协议经过优化，以提供低延迟、快速的故障检测和纠正。 可以容纳总线长度高达1000米的物理配置。本规范定义如下:a.一般说明（3.1）:LTPB协议概述。b、 物理介质接口（3.2）:本标准的这一部分定义了光学和电气总线介质的物理接口。c、 访问协议定义（3.3）:本部分标准定义了令牌传递接口单元（TPIU）的符号、帧格式、定时功能和流量记录要求。 d、 网络协议定义（3.4）:本部分标准定义了网络控制和站点管理功能。e、 测试和验证（第4节）:本段定义了LTPB测试和验证的责任和方法。f、 TPIU状态机（第5节）:本节定义TPIU状态和状态转换规则。

This standard specifies the characteristics of the SAE Linear Token Passing Bus (LTPB) Interface Unit.The LTPB provides a high reliability, high bandwidth, low latency serial interconnection network suitable for utilization in real time military and commercial applications. Multiple redundant data paths can be implemented to enhance reliability and survivability in those applications which require these attributes. The token passing and data exchange protocols are optimized to provide low latency and fast failure detection and correction. Physical configurations with bus lengths up to 1000 m can be accommodated.This specification defines the following:a. General Description (3.1): An overview of the LTPB protocol.b. Physical Media Interface (3.2): This portion of the standard defines the physical interface to both optical and electrical bus media.c. Access Protocol Definition (3.3): This portion of the standard defines the symbols, frame formats, timing functions and traffic recording requirements of the Token Passing Interface Unit (TPIU).d. Network Protocol Definition (3.4): This portion of the standard defines the network control and station management functions.e. Test and Verification (Section 4): This paragraph defines the responsibilities and methods for test and verification of the LTPB.f. TPIU State Machine (Section 5): This section defines the TPIU States and state transition rules.